Assembly:
--- suggest using 100% acetone to glue parts together
--- glue the one shamrock to each stem
--- --- gluing from the underside only is a bit neater
--- glue top to the pot
--- glue stems to the top with shamrocks pointing outward
--- ---- see stem gluing diagram

use file: shamrock_4_130511e.stl for the 4 leaf version.
shamrock_4_130511e.skp is Sketchup file with the 4 leaf